90 



made. The product of each of the selected rows is used to plant as many 

 plots the following year. Up to the present these plots have been of different 

 sizes, but now they are of equal dimensions in order that continued yielding 

 tests may be taken as an aid to field notes in the elimination of presumably 

 inferior strains. 



In ordinary line-breeding work the seed from the 100-200 selected 

 plants is planted in plots of varying sizes, depending upon the number of 

 kernels available from each plant. The average size of plot in the case of 

 autumn wheat is about .75 m. X 1.5 m. (19^" X 39"). 



Photo by L. H. N. 



FIG. XVII. Sowing pedigree plots of wheat and Rye at Svalof . Range on right Rye, 

 that on left Wheat. By alternating the ranges in this way a measure of protection 

 against crossing is afforded. 



By the head-to-the-row method it is possible to handle a much greater 

 number of different cultures than where ordinary pedigree plots are used. 

 In the former case, however, it is more difficult to judge certain characters 

 such as strength of straw, than it is in the latter. The method to be used in 

 a given case must therefore depend upon circumstances. 



Such pedigree plots or rows, as seem worthy of further consideration are preliminary 

 carried forward into larger plots for further study and comparison on the trial plots. 

 basis of yield and other qualities. These plots are called preliminary trial 



